Add graphical bar to a StringGrid col - delphi

Question

Using Delphi 2010 and a TStringGrid component, I currently display five filds from a database query.
Here is a simplied example of what i am doing
//set up the grid
procedure TGriddata.FormCreate(Sender: TObject);
begin
grdMain.Rows[0].commatext:='"One","Two","Three","Four","Five"';
grdMain.ColWidths[0]:= 50;
grdMain.ColWidths[1]:= 175;
grdMain.ColWidths[2]:= 175;
grdMain.ColWidths[3]:= 100;
grdMain.ColWidths[4]:= 300;
end;
//display the data in the grid
//note, I am not showing my creation, execution, or destroy of the query
procedure TGriddata.load;
begin
...
grdMain.Cells[0,row]:= FieldByName('one').AsString;
grdMain.Cells[1,row]:= FieldByName('two').AsString;
grdMain.Cells[2,row]:= FieldByName('three').AsString;
grdMain.Cells[3,row]:= FieldByName('four').AsString;
//draw progress bar here
...
end;
One of the columns ("Five") needs to display a navy blue horizontal bar in the col. It should also diplay some text centered in the bar. I have no expereince using the custom drawing. What properties do i set to only custom draw the one column and use the default drawing for the other columns?

Answer 1

Add the text to the cells like you normally would. But you have to draw those bars in the OnDrawCell event. Leave DefaultDrawing as is (True by default), and erase the already drawn cell text in those columns by filling it in advance:
procedure TForm1.grdMainDrawCell(Sender: TObject; ACol, ARow: Integer;
Rect: TRect; State: TGridDrawState);
var
Progress: Single;
R: TRect;
Txt: String;
begin
with TStringGrid(Sender) do
if (ACol = 4) and (ARow >= FixedRows) then
begin
Progress := StrToFloatDef(Cells[ACol, ARow], 0) / 100;
Canvas.FillRect(Rect);
R := Rect;
R.Right := R.Left + Trunc((R.Right - R.Left) * Progress);
Canvas.Brush.Color := clNavy;
Canvas.Rectangle(R);
Txt := Cells[ACol, ARow] + '%';
Canvas.Brush.Style := bsClear;
IntersectClipRect(Canvas.Handle, R.Left, R.Top, R.Right, R.Bottom);
Canvas.Font.Color := clHighlightText;
DrawText(Canvas.Handle, PChar(Txt), -1, Rect, DT_SINGLELINE or
DT_CENTER or DT_VCENTER or DT_END_ELLIPSIS or DT_NOPREFIX);
SelectClipRgn(Canvas.Handle, 0);
ExcludeClipRect(Canvas.Handle, R.Left, R.Top, R.Right, R.Bottom);
Canvas.Font.Color := clWindowText;
DrawText(Canvas.Handle, PChar(Txt), -1, Rect, DT_SINGLELINE or
DT_CENTER or DT_VCENTER or DT_END_ELLIPSIS or DT_NOPREFIX);
SelectClipRgn(Canvas.Handle, 0);
end;
end;
For more options, you might consider this DrawStatus routine.

Answer 2

Here you can view a sample (Draw percentage in a cell in a Grid), to draw a bar in a cell of a TStringGrid.
The explanation is in spanish, but you can download the code, that is very simple.
Also you can use authomatic translation on right of page.
procedure TFormDrawCell.DBGrid1DrawColumnCell(Sender: TObject;
const Rect: TRect; DataCol: Integer; Column: TColumn;
State: TGridDrawState);
const
STR_EMPTY = '';
CHAR_PERCENT = '%';
SPACE_TO_CENTER_CELLTEXT = 0;
var
fValue: Integer;
ActualPenColor, ActualBrushColor: TColor;
EmptyDS: Boolean;
DrawRect: TRect;
fWidth1, fLeft2: Integer;
StrValue: string;
begin
if not (Column.FieldName = 'Precent') then
Exit;
if not (cbdraw.Checked) then
Exit;
EmptyDS := ((TDBGrid(Sender).DataSource.DataSet.EoF) and
(TDBGrid(Sender).DataSource.DataSet.Bof));
if (Column.Field.IsNull) then begin
fValue := -1;
StrValue := STR_EMPTY;
end
else begin
fValue := Column.Field.AsInteger;
StrValue := IntToStr(fValue) + CHAR_PERCENT;
end;
DrawRect := Rect;
InflateRect(DrawRect, -1, -1);
fWidth1 := (((DrawRect.Right - DrawRect.Left) * fValue) DIV 100);
ActualPenColor := TDBGrid(Sender).Canvas.Pen.Color;
ActualBrushColor := TDBGrid(Sender).Canvas.Brush.Color;
TDBGrid(Sender).Canvas.Pen.Color := clHighlight;
TDBGrid(Sender).Canvas.Brush.Color := clWhite;
TDBGrid(Sender).Canvas.Rectangle(DrawRect);
if (fValue > 0) then begin
TDBGrid(Sender).Canvas.Pen.Color := clSkyBlue;
TDBGrid(Sender).Canvas.Brush.Color := clSkyBlue;
DrawRect.Right := DrawRect.Left + fWidth1;
InflateRect(DrawRect, -1, -1);
TDBGrid(Sender).Canvas.Rectangle(DrawRect);
end;
if not (EmptyDS) then begin
DrawRect := Rect;
InflateRect(DrawRect, -2, -2);
TDBGrid(Sender).Canvas.Brush.Style := bsClear;
fLeft2 := DrawRect.Left + (DrawRect.Right - DrawRect.Left) shr 1 -
(TDBGrid(Sender).Canvas.TextWidth(StrValue) shr 1);
TDBGrid(Sender).Canvas.TextRect(DrawRect, fLeft2,
DrawRect.Top + SPACE_TO_CENTER_CELLTEXT, StrValue);
end;
TDBGrid(Sender).Canvas.Pen.Color := ActualPenColor;
TDBGrid(Sender).Canvas.Brush.Color := ActualBrushColor;
end;
Regards.